Conventionally, in order to input and output a lot of information and programs, there has been proposed a method for inputting and outputting information, in which: a dot pattern in which fine dots are two-dimensionally arranged according to a predetermined rule is formed by printing, instead of a barcode, on a medium surface; those dots are captured and retrieved as image data by an optical reading device and digitized; and, information, such as a sound, is output.
For example, there has been proposed a method that registers information corresponding to given code information and X and Y coordinates to a storage unit in advance (for example, content data such as a sound of a text and the like visually printed on an area where a dot pattern is formed), and outputs a variety of information or executes programs by searching based on the code information and X and Y coordinates that are read out by the optical reading unit (WO2004/084125, WO2004/029871).